Hair Chair
A place for a female to sit that comprises a man's lap and, specifically, his erect manhood. Use of this phrase usually implies that more than just sitting (namely, boning) is underway.
Alex's sister is hot! I may have to let her sit on the Hair Chair.
Chair Hair
Similar to 'Bed Head' in which the hair on the back of your head is matted down from prolonged sitting.
After a nap in my new Lazy Boy, I found that I had Chair Hair.